Heat pump air-conditioning system and electric vehicle

ABSTRACT

This disclosure discloses a heat pump air-conditioning system and an electric vehicle. The system includes a HVAC assembly, a compressor, and an outdoor heat exchanger. The HVAC assembly includes an indoor condenser, an indoor evaporator, and a damper mechanism. The damper mechanism selectively opens ventilation channels of the indoor condenser and/or the indoor evaporator. An outlet of the compressor communicates to an inlet of the indoor condenser. An outlet of the indoor condenser communicates to an inlet of the outdoor heat exchanger selectively through a first throttle branch or a first through-flow branch. An outlet of the outdoor heat exchanger communicates to an inlet of the indoor evaporator selectively through a second throttle branch or a second through-flow branch. Both an outlet of the indoor evaporator, the outlet of the indoor condenser, and the outlet of the outdoor heat exchanger communicate to an inlet of the compressor.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a 371 Application of InternationalApplication No. PCT/CN2017/082949, filed on May 3, 2017, which claimspriority of Chinese Patent Application No. 201610307087.6 filed in Chinaon May 10, 2016, the entire contents of which are hereby incorporated byreference.

BACKGROUND Technical Field

This disclosure relates to the field of air conditioners of electricvehicles, and specifically to a heat pump air-conditioning system and anelectric vehicle.

Related Art

Unlike a conventional vehicle, an electric vehicle does not have excessengine heat for heating, and cannot provide a heat source for heating.Therefore, an air-conditioning system of the electric vehicle needs tohave a heat supplying function, that is, supplying heat by using a heatpump air-conditioning system and/or an electric heater.

An invention patent application having the publication No. CN105128622Adiscloses an electric-vehicle heat pump air-conditioning system. In mosturban road conditions, a time period during which external circulationof a vehicle is enabled is short, and a proportion of a load caused byenabling the external circulation to a load of the entire vehicle is nottoo high. For a vehicle, a main thermal load is transferring heat usingglass and personnel. Therefore, an effect of purely pre-cooling orpre-heating a ventilation system to improve comfort is not obvious. Inaddition, in a high-temperature working condition (an ambienttemperature is approximately 50° C. or above) or a low-temperatureworking condition (an ambient temperature is lower than −10° C.),pre-cooling or pre-heating the ventilation system is far inadequate, andit is very difficult to produce a good refrigerating or heating effectin a harsh environment.

SUMMARY

An objective of this disclosure is to provide a heat pumpair-conditioning system and an electric vehicle, to resolve a problemthat refrigerating and heating effects of a vehicle heat pumpair-conditioning system of a pure electric vehicle without an excessengine heat circulation system or a hybrid electric vehicle inelectric-only mode in a harsh environment are both unfavourable.

To achieve the foregoing objective, according to a first aspect of thisdisclosure, an electric-vehicle heat pump air-conditioning system isprovided. The heat pump air-conditioning system includes a HeatingVentilation and Air Conditioning (HVAC) assembly, a compressor, and anoutdoor heat exchanger, where the HVAC assembly includes an indoorcondenser, an indoor evaporator, and an damper mechanism, the dampermechanism is used for selectively opening a ventilation channel to theindoor condenser and/or a ventilation channel to the indoor evaporator,an outlet of the compressor is in communication with an inlet of theindoor condenser, an outlet of the indoor condenser is in communicationwith an inlet of the outdoor heat exchanger selectively through a firstthrottle branch or a first through-flow branch, an outlet of the outdoorheat exchanger is in communication with an inlet of the indoorevaporator selectively through a second throttle branch or a secondthrough-flow branch, an outlet of the indoor evaporator is incommunication with an inlet of the compressor, the outlet of the indoorcondenser is in communication with the inlet of the compressor through athird throttle branch that is selectively open or closed, and the outletof the outdoor heat exchanger is in communication with the inlet of thecompressor through a fourth throttle branch that is selectively open orclosed.

According to an embodiment of this disclosure, a first switch valve anda first throttle element are connected in series to the third throttlebranch, and a second switch valve and a second throttle element areconnected in series to the fourth throttle branch.

According to an embodiment of this disclosure, the first throttleelement is a capillary tube or an expansion valve, and the secondthrottle element is a capillary tube or an expansion valve.

According to an embodiment of this disclosure, the first through-flowbranch is provided with a third switch valve, and the first throttlebranch is provided with a first expansion valve.

According to an embodiment of this disclosure, the heat pumpair-conditioning system further includes a first expansion switch valve,an inlet of the first expansion switch valve is in communication withthe outlet of the indoor condenser, an outlet of the first expansionswitch valve is in communication with the inlet of the outdoor heatexchanger, the first throttle branch is a throttle passage of the firstexpansion switch valve, and the first through-flow branch is athrough-flow passage of the first expansion switch valve.

According to an embodiment of this disclosure, the second through-flowbranch is provided with a fourth switch valve, and the second throttlebranch is provided with a second expansion valve.

According to an embodiment of this disclosure, the heat pumpair-conditioning system is applied to an electric vehicle, and the heatpump air-conditioning system further includes a plate heat exchanger,where the plate heat exchanger is disposed inside the secondthrough-flow branch, and the plate heat exchanger is also disposedinside a motor cooling system of the electric vehicle.

According to an embodiment of this disclosure, a refrigerant inlet ofthe plate heat exchanger is in communication with the outlet of theoutdoor heat exchanger, and a refrigerant outlet of the plate heatexchanger is in communication with an inlet of the fourth switch valve.

According to an embodiment of this disclosure, the motor cooling systemincludes a motor, a motor heat dissipator, and a water pump that areconnected in series to the plate heat exchanger to form a loop.

According to an embodiment of this disclosure, the heat pumpair-conditioning system further includes a second expansion switchvalve, an inlet of the second expansion switch valve is in communicationwith the outlet of the outdoor heat exchanger, an outlet of the secondexpansion switch valve is in communication with the inlet of the indoorevaporator, the second throttle branch is a throttle passage of thesecond expansion switch valve, and the second through-flow branch is athrough-flow passage of the second expansion switch valve.

According to an embodiment of this disclosure, the heat pumpair-conditioning system is applied to an electric vehicle, and the heatpump air-conditioning system further includes a plate heat exchanger,where a refrigerant inlet of the plate heat exchanger is incommunication with the outlet of the second expansion switch valve, arefrigerant outlet of the plate heat exchanger is in communication withthe inlet of the indoor evaporator, and the plate heat exchanger is alsodisposed inside a motor cooling system of the electric vehicle.

According to an embodiment of this disclosure, the motor cooling systemincludes a coolant trunk, a first coolant branch, and a second coolantbranch, a first end of the coolant trunk is selectively in communicationwith a first end of the first coolant branch or a first end of thesecond coolant branch, and a second end of the first coolant branch anda second end of the second coolant branch are in communication with asecond end of the coolant trunk, where a motor, a motor heat dissipator,and a water pump are connected in series to the coolant trunk, and theplate heat exchanger is connected in series to the first coolant branch.

According to an embodiment of this disclosure, the heat pumpair-conditioning system further includes a gas-liquid separator, theoutlet of the indoor evaporator is in communication with an inlet of thegas-liquid separator, and an outlet of the gas-liquid separator is incommunication with the inlet of the compressor.

According to an embodiment of this disclosure, the HVAC assembly furtherincludes a PTC heater, and the PTC heater is used for heating airflowing through the indoor condenser.

According to an embodiment of this disclosure, the PTC heater isdisposed on a windward side or a leeward side of the indoor condenser.

According to a second aspect of this disclosure, an electric vehicle isprovided. The electric vehicle includes the foregoing heat pumpair-conditioning system.

The heat pump air-conditioning system provided in this disclosure cancontrol processes, such as refrigerating and heating, of a vehicleair-conditioning system without changing a refrigerant circulationdirection. In addition, a plurality of throttle branches is added to thesystem to enable the system to have a good refrigerating effect at ahigh temperature and a good heating effect at a low temperature whilehaving a good defrosting effect. In this disclosure, an air flowingdirection in the indoor evaporator and the indoor condenser in the HVACassembly may be independently controlled and adjusted by using thedamper mechanism, that is, during refrigerating, air flows through onlythe indoor evaporator, no air passes through the indoor condenser, andthe indoor condenser is merely used as a refrigerant passage; and duringheating, air flows through only the indoor condenser, no air passesthrough the indoor evaporator, and the indoor evaporator is merely usedas a refrigerant passage. In addition, because the heat pumpair-conditioning system of this disclosure employs only one outdoor heatexchanger, air resistance against a front end module of a vehicle can bereduced, problems, such as low heating energy efficiency, impossibilityin satisfying regulatory requirements for defrosting and defogging, andcomplex installation, of a vehicle heat pump air-conditioning system ofa pure electric vehicle without an excess engine heat circulation systemor a hybrid electric vehicle in electric-only mode are resolved, andeffects of reducing energy consumption, simplifying a system structure,and facilitating pipeline arrangement are achieved. The heat pumpair-conditioning system provided in this disclosure features a simplestructure, and therefore, can be easily mass produced.

Other features and advantages of this disclosure are described in detailin the Detailed Description part below.

BRIEF DESCRIPTION OF THE DRAWINGS

Accompanying drawings are used to provide further understanding on thisdisclosure, constitute a part of this specification, and are used,together with the following specific implementations, to explain thisdisclosure, but do not constitute limitations to this disclosure,wherein:

FIG. 1 is a schematic structural diagram of a heat pump air-conditioningsystem according to an implementation of this disclosure;

FIG. 2 is a schematic structural diagram of a heat pump air-conditioningsystem according to another implementation of this disclosure;

FIG. 3 is a schematic structural diagram of a heat pump air-conditioningsystem according to another implementation of this disclosure;

FIG. 4a is a schematic structural diagram of a heat pumpair-conditioning system according to another implementation of thisdisclosure;

FIG. 4b is a schematic structural diagram of a heat pumpair-conditioning system according to another implementation of thisdisclosure;

FIG. 5 is a schematic structural diagram of a heat pump air-conditioningsystem according to another implementation of this disclosure;

FIG. 6 is a schematic structural diagram of a heat pump air-conditioningsystem according to another implementation of this disclosure;

FIG. 7 is a schematic structural diagram of a heat pump air-conditioningsystem according to another implementation of this disclosure;

FIG. 8 is a schematic structural diagram of a heat pump air-conditioningsystem according to another implementation of this disclosure;

FIG. 9 is a schematic structural diagram of a heat pump air-conditioningsystem according to another implementation of this disclosure;

FIG. 10 is a schematic structural diagram of a heat pumpair-conditioning system according to another implementation of thisdisclosure;

FIG. 11 is a schematic top structural view of an expansion switch valveaccording to a preferred implementation of this disclosure;

FIG. 12 is a schematic sectional structural view along a midline AB-ABin FIG. 11, where a first valve port and a second valve port are both inan open state;

FIG. 13 is a schematic front structural view of an expansion switchvalve from a perspective according to a preferred implementation of thisdisclosure;

FIG. 14 is a schematic sectional structural view along a midline AB-ABin FIG. 11, where a first valve port is in an open state, and a secondvalve port is in a closed state;

FIG. 15 is a schematic sectional structural view along a midline AB-ABin FIG. 11, where a first valve port is in a closed state, and a secondvalve port is in an open state;

FIG. 16 is a schematic front structural view of an expansion switchvalve from another perspective according to a preferred implementationof this disclosure;

FIG. 17 is a schematic sectional structural view along a midline AC-ACin FIG. 16, where a first valve port is in an open state, and a secondvalve port is in a closed state;

FIG. 18 is a first schematic internal structural diagram of an expansionswitch valve according to a preferred implementation of this disclosure,where a first valve port and a second valve port are both in an openstate;

FIG. 19 is a partial enlarged diagram of a part A in FIG. 18;

FIG. 20 is a second schematic internal structural diagram of anexpansion switch valve according to a preferred implementation of thisdisclosure, where a first valve port is in an open state, and a secondvalve port is in a closed state; and

FIG. 21 is a third schematic internal structural diagram of an expansionswitch valve according to a preferred implementation of this disclosure,where a first valve is port in a closed state, and a second valve portis in an open state.

DETAILED DESCRIPTION

Specific implementations of this disclosure are described in detailbelow with reference to the accompanying drawings. It should beunderstood that the specific implementations described herein are merelyused to describe and explain this disclosure rather than limit thisdisclosure.

In this disclosure, unless contrarily described, the used localityterms, such as “up, down, left, and right”, are usually relative tographical directions of the accompanying drawings. “Upstream anddownstream” are relative to a flowing direction of a medium such as arefrigerant. Specifically, being in a direction the same as a flowingdirection of the refrigerant is being downstream, and being in adirection opposite to the flowing direction of the refrigerant is beingupstream. “Inside and outside” indicate being inside and outside acontour of a corresponding component.

In addition, in this disclosure, an electric vehicle may be a pureelectric vehicle, a hybrid electric vehicle, and a fuel cell vehicle.

FIG. 1 is a schematic structural diagram of a heat pump air-conditioningsystem according to an implementation of this disclosure. As shown inFIG. 1A, the system may include: an HVAC assembly 600, a compressor 604,and an outdoor heat exchanger 605. The HVAC assembly 600 may include anindoor condenser 601, an indoor evaporator 602, and a damper mechanism(not shown), and the damper mechanism may be used for selectivelyopening a ventilation channel to the indoor condenser 601 and/or aventilation channel to the indoor evaporator 602.

In this disclosure, in the HVAC assembly, opening and closure of theventilation channel to the indoor condenser 601 and the ventilationchannel to the indoor evaporator 602 may be independently controlled byusing the damper mechanism. That is, air may be controlled to flowthrough only the indoor condenser 601, or only the indoor evaporator602, or both the indoor condenser 601 and the indoor evaporator 602 byusing the damper mechanism. Therefore, independent control on an airdirection can be implemented.

In addition, as shown in FIG. 1A, an outlet of the compressor 604 is incommunication with an inlet of the indoor condenser 601, an outlet ofthe indoor condenser 601 is in communication with an inlet of theoutdoor heat exchanger 605 selectively through a first throttle branchor a first through-flow branch, an outlet of the outdoor heat exchanger605 is in communication with an inlet of the indoor evaporator 602selectively through a second throttle branch or a second through-flowbranch, and an outlet of the indoor evaporator 602 is in communicationwith an inlet of the compressor 604. The outlet of the indoor condenser601 is further in communication with the inlet of the compressor 604through a third throttle branch that is selectively open or closed,where the third throttle branch is open during low-temperature heating,so that a vehicle has a good heating effect at a low temperature; anoutlet of the outdoor heat exchanger 605 is further in communicationwith the inlet of the compressor 604 through a fourth throttle branchthat is selectively open or closed, the fourth throttle branch is openduring high-temperature refrigerating, so that a vehicle has a goodrefrigerating effect at a high temperature.

Specifically, as shown in FIG. 1, the third throttle branch may beconnected in series to a first switch valve 620 and a first throttleelement 621, and preferably, the first switch valve 620 is disposedupstream of the first throttle element 621, to enable the system torespond quickly; and the fourth throttle branch may be connected inseries to a second switch valve 622 and a second throttle element 623,and preferably, the second switch valve 622 is disposed upstream of thesecond throttle element 623, to enable the system to respond quickly.The first switch valve 620 and the second switch valve 622 are used forcontrolling opening or closure of corresponding branches, and the firstthrottle element 621 and the second throttle element 623 are used forcontrolling throttle functions of corresponding branches.

Further, the first throttle element 621 may be a capillary tube or anexpansion valve, and the second throttle element 623 may be a capillarytube or an expansion valve. Forms of the first throttle element 621 andthe second throttle element 623 are not specifically limited herein,provided that a throttle function can be implemented, that is, atemperature reduction and/or pressure reduction function is implemented.For example, in FIG. 4a , the first throttle element 621 and the secondthrottle element 623 may separately be expansion valves, and in FIG. 4b, the first throttle element 621 and the second throttle element 623 mayseparately be capillary tubes.

In this disclosure, the outlet of the indoor condenser 601 is incommunication with the inlet of the outdoor heat exchanger 605 througheither the first throttle branch or the first through-flow branch. Sucha communication manner can be implemented in various manners. In anotherimplementation, as shown in FIG. 1, the heat pump air-conditioningsystem may include a third switch valve 608 and a first expansion valve607, where the third switch valve 608 is disposed on the firstthrough-flow branch, and the first expansion valve 607 is disposed onthe first throttle branch. Specifically, as shown in FIG. 1, the outletof the indoor condenser 601 is in communication with the inlet of theoutdoor heat exchanger 605 through the third switch valve 608 to formthe first through-flow branch, and the outlet of the indoor condenser601 is in communication with the inlet of the outdoor heat exchanger 605through the first expansion valve 607 to form the first throttle branch.When the system is in refrigerating mode, the third switch valve 608 isopen, the first expansion valve 607 is closed, and the outlet of theindoor condenser 601 is in communication with the inlet of the outdoorheat exchanger 605 through the first through-flow branch. When thesystem is in heating mode, the first expansion valve 607 is open, thethird switch valve 608 is closed, and the outlet of the indoor condenser601 is in communication with the inlet of the outdoor heat exchanger 605through the first throttle branch.

In another alternative implementation, as shown in FIG. 2, the heat pumpair-conditioning system may further include a first expansion switchvalve 603, an inlet of the first expansion switch valve 603 is incommunication with the outlet of the indoor condenser 601, and an outletof the first expansion switch valve 603 is in communication with theinlet of the outdoor heat exchanger 605, where the first throttle branchis a throttle passage of the first expansion switch valve 603, and thefirst through-flow branch is a through-flow passage of the firstexpansion switch valve 603.

In this disclosure, the expansion switch valve is a valve having both anexpansion valve function (also referred to as an electronic expansionvalve function) and a switch valve function (also referred to as anelectromagnetic valve function), and may be considered as a combinationof a switch valve and an expansion valve. A through-flow passage and athrottle passage are formed inside the expansion switch valve, and whenthe expansion switch valve is used as a switch valve, the through-flowpassage inside it is open, and in this case, a through-flow branch isformed; and when the expansion switch valve is used as an expansionvalve, a throttle passage inside it is open, and in this case, athrottle branch is formed.

Similar to the implementations of the first through-flow branch and thefirst throttle branch, in one of the implementations of the secondthrough-flow branch and the second throttle branch, as shown in FIG. 1,the heat pump air-conditioning system may further include a fourthswitch valve 610 and a second expansion valve 609, where the secondthrough-flow branch is provided with a fourth switch valve 610, and thesecond throttle branch is provided with the second expansion valve 609.Specifically, as shown in FIG. 1, the outlet of the outdoor heatexchanger 605 is in communication with the inlet of the indoorevaporator 602 through the fourth switch valve 610 to form the secondthrough-flow branch, and the outlet of the outdoor heat exchanger 605 isin communication with the inlet of the indoor evaporator 602 through thesecond expansion valve 609 to form the second throttle branch. When thesystem is in refrigerating mode, the second expansion valve 609 is open,the fourth switch valve 610 is closed, and the outlet of the outdoorheat exchanger 605 is in communication with the inlet of the indoorevaporator 602 through the second throttle branch. When the system is inheating mode, the fourth switch valve 610 is open, the second expansionvalve 609 is closed, and the outlet of the outdoor heat exchanger 605 isin communication with the inlet of the indoor evaporator 602 through thesecond throttle branch.

In another alternative implementation, as shown in FIG. 3, the heat pumpair-conditioning system may further include a second expansion switchvalve 606, an inlet of the second expansion switch valve 606 is incommunication with the outlet of the outdoor heat exchanger 605, and anoutlet of the second expansion switch valve 606 is in communication withthe inlet of the indoor evaporator 602, where the second throttle branchis a throttle passage of the second expansion switch valve 606, and thesecond through-flow branch is a through-flow passage of the secondexpansion switch valve 606.

To facilitate pipeline arrangement and save an occupied space,preferably, the first expansion switch valve 603 and the secondexpansion switch valve 606, that is, an implementation shown in FIG. 4a, are used in the heat pump air-conditioning system provided in thisdisclosure.

FIG. 4a is a schematic structural diagram of a heat pumpair-conditioning system according to another implementation of thisdisclosure. As shown in FIG. 4a , the heat pump air-conditioning systemmay further include a gas-liquid separator 611, where the outlet of theindoor evaporator 602 is in communication with an inlet of thegas-liquid separator 611, and an outlet of the gas-liquid separator 611is in communication with the inlet of the compressor 604. In this way, arefrigerant flowing out through the indoor evaporator 602 can first passthrough the gas-liquid separator 611 to be subject to gas-liquidseparation, and the separated gas flows back to the compressor 604, toprevent the liquid refrigerant from entering the compressor 604 anddamaging the compressor 604, so that a service life of the compressor604 can be prolonged, and efficiency of the entire heat pumpair-conditioning system can be improved.

FIG. 4a to FIG. 7 are used as examples below to specifically describecirculation processes and principles of the heat pump air-conditioningsystem provided in this disclosure in different working modes. It shouldbe understood that circulation processes and principles of the system inother implementations (for example, the implementations shown in FIG. 1to FIG. 3) are similar to those in FIG. 4a to FIG. 7, and details arenot described herein again.

Mode 1: High-Temperature Refrigerating Mode.

When the system is in this mode, the entire system forms ahigh-temperature refrigerating circulation system. As shown in FIG. 4aand FIG. 4b , first, the compressor 604 discharges a high-temperaturehigh-pressure gas by means of compression, and the compressor 604 isconnected to the indoor condenser 601. In this case, the dampermechanism controls air to not pass through the indoor condenser 601.Because no air passes through the indoor condenser 601, heat exchange isnot performed inside the indoor condenser 601, and the indoor condenser601 is merely used as a passage. In this case, the high-temperaturehigh-pressure gas remains unchanged at the outlet of the indoorcondenser 601. The outlet of the indoor condenser 601 is incommunication with the inlet of the first expansion switch valve 603. Inthis case, the first expansion switch valve 603 implements a switchvalve function, and is merely used as a passage. In this case, thehigh-temperature high-pressure gas remains unchanged at the outlet ofthe first expansion switch valve 603. The outlet of the first expansionswitch valve 603 is in communication with the inlet of the outdoor heatexchanger 605, the outdoor heat exchanger 605 exchanges heat withoutdoor air, and dissipates heat into air, and a moderate-temperaturehigh-pressure liquid is generated at the outlet of the outdoor heatexchanger 605. The outlet of the outdoor heat exchanger 605 is incommunication with the inlet of the second expansion switch valve 606.In this case, the second expansion switch valve 606 implements anexpansion valve function, and implements a throttle function as athrottle element, and a low-temperature low-pressure liquid is generatedat the outlet thereof. An opening degree of the second expansion switchvalve 606 may be set according to actual requirements, and the openingdegree may be adjusted by calculating a superheat degree of therefrigerant at the outlet of the evaporator according to pressure andtemperature data collected by a pressure-temperature sensor mountedbetween the outlet of the indoor evaporator 602 and the inlet of thegas-liquid separator 611. The outlet of the second expansion switchvalve 606 is in communication with the inlet of the indoor evaporator602, and the low-temperature low-pressure liquid is evaporated in theindoor evaporator 602, so that a low-temperature low-pressure gas isgenerated at the outlet of the indoor evaporator 602, but because ofimpact of a high-temperature environment, an overheated over-temperaturegaseous refrigerant is generated at the outlet of the indoor evaporator602. Meanwhile, the third throttle branch is closed, and the fourththrottle branch is open. The moderate-temperature high-pressure liquidfrom the outlet of the outdoor heat exchanger 605 changes into alow-temperature low-pressure gaseous-liquid refrigerant under thethrottling action of the second throttle element 623. The gaseous-liquidrefrigerant and the foregoing overheated over-temperature gaseousrefrigerant converge to perform heat exchange, so that a suctiontemperature, a discharge temperature, and power consumption of thecompressor 604 can be reduced in a high-temperature environment. Theindoor evaporator 602 is connected to the gas-liquid separator 611, theliquid that is not evaporated is separated by the gas-liquid separator611, and finally, the low-temperature low-pressure gas returns to thecompressor 604, so that a cycle is formed. In this case, air in the HVACassembly 600 flows through only the indoor evaporator 602, no air passesthrough the indoor condenser 601, and the indoor condenser 601 is merelyused as a refrigerant passage.

Mode 2: Ordinary-Temperature Refrigerating Mode.

When the system is in this mode, the entire system forms anordinary-temperature refrigerating circulation system. As shown in FIG.5, in this mode, the entire system is similar to the system in thehigh-temperature refrigerating mode, and a difference lies in that inthis mode, both of the third throttle branch and the fourth throttlebranch are closed because at an ordinary temperature, a low-temperaturelow-pressure gas may be generated at the outlet of the indoor evaporator602, no overheated over-temperature gaseous refrigerant is generated, sothat the throttle function of the fourth throttle branch is not needed.In this way, unnecessary energy waste can be reduced, and the workingefficiency of the system can be improved.

Mode 3: Low-Temperature Heating Mode.

When the system is in this mode, the entire system forms alow-temperature heating circulation system. As shown in FIG. 6, first,the compressor 604 discharges a high-temperature high-pressure gas bymeans of compression, the compressor 604 is connected to the indoorcondenser 601, and the high-temperature high-pressure gas is condensedin the indoor condenser 601, so that a moderate-temperaturehigh-pressure liquid is generated at the outlet of the indoor condenser601. The outlet of the indoor condenser 601 is in communication with theinlet of the first expansion switch valve 603. In this case, the firstexpansion switch valve 603 implements an expansion valve function, andimplements a throttle function as a throttle element, and alow-temperature low-pressure liquid is generated at the outlet thereof.An opening degree of the first expansion switch valve 603 may be setaccording to actual requirements, and the opening degree may be adjustedaccording to temperature data (that is, a discharge temperature of thecompressor) collected by a pressure-temperature sensor mounted at theoutlet of the compressor 604. The outlet of the first expansion switchvalve 603 is in communication with the inlet of the outdoor heatexchanger 605, the outdoor heat exchanger 605 absorbs heat from outdoorair, and a low-temperature low-pressure gas is generated at the outletof the outdoor heat exchanger 605. The outlet of the outdoor heatexchanger 605 is in communication with the inlet of the second expansionswitch valve 606. In this case, the second expansion switch valve 606implements a switch valve function, and is merely used as a passage. Theoutlet of the second expansion switch valve 606 is in communication withthe inlet of the indoor evaporator 602. Air is controlled, by using thedamper mechanism, to flow toward only the indoor condenser 601 insteadof flowing toward the indoor evaporator 602, so that heat exchange isnot performed in the indoor evaporator 602, the indoor evaporator 602 ismerely used as a passage, and the low-temperature low-pressure gasremains unchanged at the outlet thereof. However, due to impact of alow-temperature environment, a subcooled over-low-temperature gaseousrefrigerant is generated at the outlet of the indoor evaporator 602.Meanwhile, the fourth throttle branch is closed, and the third throttlebranch is open. The moderate-temperature high-pressure liquid from theoutlet of the outdoor heat exchanger 601 changes into amoderate-temperature low-pressure gaseous-liquid refrigerant under thethrottling action of the first throttle element 621. The gaseous-liquidrefrigerant and the foregoing subcooled over-low-temperature gaseousrefrigerant converge to perform heat exchange, so that a suction amount,a suction temperature, and a discharge temperature of the compressor 604can be increased in the low-temperature environment, so as to increasean amount of exchanged heat of the indoor condenser 601, therebyimproving heating comfort, the system energy efficiency, and thecompressor efficiency. The converged gaseous-liquid refrigerant flows tothe gas-liquid separator 611, the liquid that is not evaporated isseparated by the gas-liquid separator 611, and finally, thelow-temperature low-pressure gas returns to the compressor 604, so thata cycle is formed. In this case, air in the HVAC assembly 600 flowsthrough only the indoor condenser 601, no air passes through the indoorevaporator 602, and the indoor evaporator 602 is merely used as arefrigerant passage.

Mode 4: Ordinary-Temperature Heating Mode.

When the system is in this mode, the entire system forms anordinary-temperature heating circulation system. As shown in FIG. 7, inthis mode, the entire system is similar to the system in thelow-temperature heating mode, and a difference lies in that in thismode, both of the third throttle branch and the fourth throttle branchare closed because at an ordinary temperature, no subcooledover-low-temperature gaseous refrigerant is generated at the outlet ofthe indoor evaporator 602, so that the throttle function of the thirdthrottle branch is not needed. In this way, unnecessary energy waste canbe reduced, and the working efficiency of the system can be improved.

Mode 5: Outdoor Heat Exchanger Defrosting Mode.

As shown in FIG. 5, first, the compressor 604 discharges ahigh-temperature high-pressure gas by means of compression, and thecompressor 604 is connected to the indoor condenser 601. In this case,the indoor condenser 601 is merely used as a passage, and thehigh-temperature high-pressure gas remains unchanged at the outlet ofthe indoor condenser 601. The outlet of the indoor condenser 601 is incommunication with the inlet of the first expansion switch valve 603. Inthis case, the first expansion switch valve 603 implements a switchvalve function, and is merely used as a passage, and thehigh-temperature high-pressure gas remains unchanged at the outlet ofthe first expansion switch valve 603. The outlet of the first expansionswitch valve 603 is in communication with the inlet of the outdoor heatexchanger 605, the outdoor heat exchanger 605 exchanges heat withoutdoor air, and dissipates heat into air, and a moderate-temperaturehigh-pressure liquid is generated at the outlet of the outdoor heatexchanger 605. The outlet of the outdoor heat exchanger 605 is incommunication with the inlet of the second expansion switch valve 606.In this case, the second expansion switch valve 606 implements anexpansion valve function, and implements a throttle function as athrottle element, and a low-temperature low-pressure liquid is generatedat the outlet thereof. An opening degree of the second expansion switchvalve 606 may be set according to actual requirements, and the openingdegree may be adjusted by calculating a superheat degree of therefrigerant at the outlet of the evaporator according to pressure andtemperature data collected by a pressure-temperature sensor mountedbetween the outlet of the indoor evaporator 602 and the inlet of thegas-liquid separator 611. The outlet of the second expansion switchvalve 606 is in communication with the inlet of the indoor evaporator602, and a low-temperature and low-pressure gas is generated at theoutlet of the indoor evaporator 602. The indoor evaporator 602 isconnected to the gas-liquid separator 611, the liquid that is notevaporated is separated by the gas-liquid separator 611, and finally,the low-temperature low-pressure gas returns to the compressor 604, sothat a cycle is formed. In this case, both the third throttle branch andthe fourth throttle branch are closed. In this case, ventilation of theHVAC assembly 600 does not need to be enabled.

In conclusion, the heat pump air-conditioning system provided in thisdisclosure can control processes, such as refrigerating and heating, ofa vehicle air-conditioning system without changing a refrigerantcirculation direction. In addition, a plurality of throttle branches isadded to the system to enable the system to have a good refrigeratingeffect at a high temperature and a good heating effect at a lowtemperature while having a good defrosting effect. In this disclosure,an air flowing direction in the indoor evaporator and the indoorcondenser in the HVAC assembly may be independently controlled andadjusted by using the damper mechanism, that is, during refrigerating,air flows through only the indoor evaporator, no air passes through theindoor condenser, and the indoor condenser is merely used as arefrigerant passage; and during heating, air flows through only theindoor condenser, no air passes through the indoor evaporator, and theindoor evaporator is merely used as a refrigerant passage. In addition,because the heat pump air-conditioning system of this disclosure employsonly one outdoor heat exchanger, air resistance against a front endmodule of a vehicle can be reduced, problems, such as low heating energyefficiency, impossibility in satisfying regulatory requirements fordefrosting and defogging, and complex installation, of a vehicle heatpump air-conditioning system of a pure electric vehicle without anexcess engine heat circulation system or a hybrid electric vehicle inelectric-only mode are resolved, and effects of reducing energyconsumption, simplifying a system structure, and facilitating pipelinearrangement are achieved. The heat pump air-conditioning system providedin this disclosure features a simple structure, and therefore, can beeasily mass produced.

In the low-temperature heating mode and the ordinary-temperature heatingmode, to improve the heating capability, preferably, as shown in FIG. 8and FIG. 9, a plate heat exchanger 612 is disposed inside the entireheat pump air-conditioning system, and the plate heat exchanger 612 isalso disposed inside a motor cooling system of an electric vehicle. Inthis way, a refrigerant of the air-conditioning system can be heated byusing excess heat of the motor cooling system, thereby improving asuction temperature and a suction amount of the compressor 604.

For example, as shown in FIG. 8, in an implementation in which thesecond expansion valve 609 and the fourth switch valve 610 are used inthe heat pump air-conditioning system, the plate heat exchanger 612 maybe disposed inside the second through-flow branch, as shown in FIG. 8.For example, in an implementation, a refrigerant inlet 612 a of theplate heat exchanger 612 is in communication with the outlet of theoutdoor heat exchanger 605, and a refrigerant outlet 612 b of the plateheat exchanger 612 is in communication with an inlet of the fourthswitch valve 610. Alternatively, in another implementation (not shown),a refrigerant inlet 612 a of the plate heat exchanger 612 may also be incommunication with an outlet of the fourth switch valve 610, and arefrigerant outlet 612 b of the plate heat exchanger 612 is incommunication with the inlet of the indoor evaporator 602.

In addition, the plate heat exchanger 612 is also disposed inside themotor cooling system. As shown in FIG. 8, the motor cooling system mayinclude a motor, a motor heat dissipator 613, and a water pump 614 thatare connected in series to the plate heat exchanger 612 to form a loop.In this way, the refrigerant can perform heat exchange with a coolant inthe motor cooling system by using the plate heat exchanger 612. Afterpassing through the fourth switch valve 610 and the indoor evaporator602, the low-temperature low-pressure gas remains unchanged at theoutlet of the indoor evaporator 602. In this case, the fourth switchvalve 610 and the indoor evaporator 602 are merely used as passages.

Alternatively, as shown in FIG. 9, in an implementation in which thesecond expansion switch valve 606 is used in the heat pumpair-conditioning system, a refrigerant inlet 612 a of the plate heatexchanger 612 is in communication with the outlet of the secondexpansion switch valve 606, a refrigerant outlet 612 b of the plate heatexchanger 612 is in communication with the inlet of the indoorevaporator 602, and the plate heat exchanger 612 is also disposed insidethe motor cooling system of the electric vehicle. In this way, therefrigerant can perform heat exchange with a coolant in the motorcooling system by using the plate heat exchanger 612.

The heating capability of the air-conditioning system in thelow-temperature heating mode and the ordinary-temperature heating modecan be improved by using the plate heat exchanger 612.

However, as shown in FIG. 9, in the implementation in which the secondexpansion switch valve 606 is used in the heat pump air-conditioningsystem, to avoid heating the refrigerant in the high-temperaturerefrigerating mode and the outdoor heat exchanger defrosting mode, avalve may be used to control whether heat exchange is performed in theplate heat exchanger 612. Specifically, the motor cooling system mayinclude a coolant trunk 616, a first coolant branch 617, and a secondcoolant branch 618, a first end of the coolant trunk 616 is selectivelyin communication with a first end of the first coolant branch 617 or afirst end of the second coolant branch 618. For example, in animplementation, the first end of the coolant trunk 616 may be incommunication with an inlet 615 a of a three-way valve 615, the firstend of the first coolant branch 617 may be in communication with a firstoutlet 615 b of the three-way valve 615, the first end of the secondcoolant branch 618 may be in communication with a second outlet 615 c ofthe three-way valve 615. Therefore, the first end of the coolant trunk616 may be controlled, by using the three-way valve 615, to beselectively in communication with the first end of the first coolantbranch 617 or the first end of the second coolant branch 618. Inaddition, as shown in FIG. 9, a second end of the first coolant branch617 is in communication with a second end of the coolant trunk 616, anda second end of the second coolant branch 618 is also in communicationwith the second end of the coolant trunk 616; a motor, a motor heatdissipator 613, and a water pump 614 are connected in series to thecoolant trunk 616, and the plate heat exchanger 612 is connected inseries to the first coolant branch 617.

In this way, when the air-conditioning system works in thelow-temperature heating mode or the ordinary-temperature heating mode,to improve the heating capability, the refrigerant needs to be heated inthe plate heat exchanger 612. Therefore, in this case, the first coolantbranch 617 may be opened by controlling the three-way valve 615, so thatthe coolant in the motor cooling system flows through the plate heatexchanger 612. In this case, heat exchange with the refrigerant can beimplemented. However, when the system works in the high-temperaturerefrigerating mode, the ordinary-temperature refrigerating mode, or theoutdoor heat exchanger defrosting mode, the refrigerant does not need tobe heated in the plate heat exchanger 612. Therefore, in this case, thesecond coolant branch 618 may be opened by controlling the three-wayvalve 615, so that the coolant in the motor cooling system does not flowthrough the plate heat exchanger 612. In this case, the plate heatexchanger 612 is merely used as a passage of the refrigerant.

In the heat pump air-conditioning system provided in this disclosure,various refrigerants, such as R134a, R410a, R32, and R290, may be used.Preferably, a moderate- and high-temperature refrigerant is used.

FIG. 10 is a schematic structural diagram of a heat pumpair-conditioning system according to another implementation of thisdisclosure. As shown in FIG. 10, the HVAC assembly 600 may furtherinclude a PTC heater 619, and the PTC heater 619 is used for heating airflowing through the indoor condenser 601.

In this disclosure, the PTC heater 619 may be a high-voltage PTC heater(which is driven by high-voltage batteries in the entire vehicle), and avoltage range is 200 V to 900 V. Alternatively, the PTC heater 619 maybe a low-voltage PTC heater (which is driven by a 12 V- or 24 V-storagebattery), and a voltage range is 9 V to 32 V. In addition, the PTCheater 619 may be a complete core formed by several strip-shaped orseveral block-shaped PTC ceramic wafer modules and a heat dissipationfin, or may be a strip-shaped or block-shaped PTC ceramic wafer modulehaving a heat dissipation fin.

In this disclosure, the PTC heater 619 may be disposed on a windwardside or a leeward side of the indoor condenser 601. In addition, toimprove an effect of heating air flowing through the indoor condenser601, the PTC heater 619 may be disposed in parallel to the indoorcondenser 601. In other implementations, the PTC heater 619 mayalternatively be disposed at a foot blowing air vent and a defrostingvent of a box of the HVAC assembly 600, or may be disposed at an airvent of a defrosting ventilation channel.

If the PTC heater 619 is disposed on the windward side or the leewardside of the indoor condenser 601 in the box and is disposed in parallelto the indoor condenser 601, a groove may be dug on a housing of thebox, and the PTC heater 619 is perpendicularly inserted into the box;alternatively, a support may be welded on a sideboard of the indoorcondenser 601, and the PTC heater 619 is fastened to the support of theindoor condenser 601 by using screws. If the PTC heater 619 is disposedat the foot blowing air vent and the defrosting vent of the box or isdisposed at the air vent of the defrosting ventilation channel, the PTCheater 619 may be directly fastened to the air outlets of the box andthe air vent of the ventilation channel by using screws.

According to the implementation, when the temperature outside thevehicle is too low and a heating amount in the low-temperature heatingmode of the heat pump air-conditioning system cannot satisfy arequirement in the vehicle, the PTC heater 619 may be run to assistheating. Therefore, disadvantages, such as a small heating amount, slowentire-vehicle defrosting and defogging, and a poor heating effect, ofthe heat pump air-conditioning system in the low-temperature heatingmode can be eliminated.

As described above, in this disclosure, the expansion switch valve is avalve having both an expansion valve function and a switch valvefunction, and may be considered as a combination of a switch valve andan expansion valve. An exemplary implementation of the expansion switchvalve is provided below.

As shown in FIG. 11, the foregoing mentioned expansion switch valve mayinclude a valve body 500, where an inlet 501, an outlet 502, and aninternal passage in communication between the inlet 501 and the outlet502 are formed on the valve body 500, a first valve plug 503 and asecond valve plug 504 are mounted on the internal passage, the firstvalve plug 503 makes the inlet 501 and the outlet 502 in directcommunication or out of communication, and the second valve plug 504makes the inlet 501 and the outlet 502 in communication through athrottle port 505 or out of communication.

The “direct communication” implemented by the first valve plug meansthat the refrigerant entered from the inlet 501 of the valve body 500can bypass the first valve plug and directly flow to the outlet 502 ofthe valve body 500 through the internal passage without being affected,and the “out of communication” implemented by the first valve plug meansthat the refrigerant entered from the inlet 501 of the valve body 500cannot bypass the first valve plug and cannot flow to the outlet 502 ofthe valve body 500 through the internal passage. The “communicationthrough a throttle port” implemented by the second valve plug means thatthe refrigerant entered from the inlet 501 of the valve body 500 canbypass the second valve plug and flow to the outlet 502 of the valvebody 500 after being throttled by a throttle port, and the “out ofcommunication” implemented by the second valve plug means that therefrigerant entered from the inlet 501 of the valve body 500 cannotbypass the second valve plug and cannot flow to the outlet 502 of thevalve body 500 through the throttle port 505.

In this way, the expansion switch valve in this disclosure can achieveat least three states of the refrigerant entered from the inlet 501 bycontrolling the first valve plug and the second valve plug: (1) a closedstate; (2) a direct communication state by bypassing the first valveplug 503; and (3) a throttled communication manner by bypassing thesecond valve plug 504.

After being throttled by the throttle port 505, a high-temperaturehigh-pressure liquid refrigerant may become a low-temperaturelow-pressure atomized liquid refrigerant. This creates a condition forevaporation of the refrigerant. That is, a cross sectional area of thethrottle port 505 is smaller than a cross sectional area of the outlet502, and an opening degree of the throttle port 505 may be adjusted bycontrolling the second valve plug, to control an amount of flow passingthrough the throttle port 505, thereby avoiding insufficientrefrigeration caused by an excessively small amount of refrigerant andavoiding a liquid slugging phenomenon in the compressor that is causedby an excessively large amount of refrigerant. That is, cooperationbetween the second valve plug 504 and the valve body 500 can make theexpansion switch valve have the expansion valve function.

In this way, an opening/closure control function and/or a throttlecontrol function of the inlet 501 and the outlet 502 can be implementedby mounting the first valve plug 503 and the second valve plug 504 onthe internal passage of the same valve body 500. A structure is simple,and production and installation are easy. In addition, when theexpansion switch valve provided in this disclosure is applied to a heatpump system, a filling amount of refrigerant of the entire heat pumpsystem is reduced, costs are reduced, pipeline connections aresimplified, and oil return of the heat pump system is facilitated.

As an exemplary internal installation structure of the valve body 500,as shown in FIG. 11 to FIG. 16, the valve body 500 includes a valve base510 that forms an internal passage and a first valve housing 511 and asecond valve housing 512 that are mounted on the valve base 510. A firstelectromagnetic drive portion 521 used for driving the first valve plug503 is mounted in the first valve housing 511, and a secondelectromagnetic drive portion 522 used for driving the second valve plug504 is mounted in the second valve plug 504. The first valve plug 503extends from the valve housing 511 to the internal passage inside thevalve base 510, and the second valve plug 504 extends from an endproximal to the second valve housing 512 to the internal passage insidethe valve base 510.

A location of the first valve plug 503 can be easily controlled bycontrolling power-on or power-off of the first electromagnetic driveportion 521 (for example, an electromagnetic coil), to controldirect-communication or out-of-communication between the inlet 501 andthe outlet 502. A location of the second valve plug 504 can be easilycontrolled by controlling power-on or power-off of the secondelectromagnetic drive portion 522 (for example, an electromagneticcoil), to control whether the inlet 501 and the outlet 502 are incommunication with the throttle port 505. In other words, an electronicexpansion valve and an electromagnetic valve that share the inlet 501and the outlet 502 are connected in parallel and mounted in the valvebody 500. Therefore, automated control on opening/closure and/orthrottling of the expansion switch valve can be implemented, andpipeline arrangement can be simplified.

To fully use spatial locations of the expansion switch valve indifferent directions and avoid connections between the expansion switchvalve and different pipelines from interfering with each other, thevalve base 510 is of a polyhedral structure, the first valve housing511, the second valve housing 512, the inlet 501, and the outlet 502 arerespectively disposed on different surfaces of the polyhedral structure,installation directions of the first valve housing 511 and the secondvalve housing 512 are perpendicular to each other, and openingdirections of the inlet 501 and the outlet 502 are perpendicular to eachother. In this way, inlet and outlet pipelines can be connected to thedifferent surfaces of the polyhedral structure, thereby avoiding aproblem of disordered and twisted pipeline arrangement.

As a typical internal structure of the expansion switch valve, as shownin FIG. 11 to FIG. 14, the internal passage includes a first passage 506and a second passage 507 that are separately in communication with theinlet 501, a first valve port 516 fitting the first valve plug 503 isformed on the first passage 506, the throttle port 505 is formed on thesecond passage 507 to form a second valve port 517 fitting the secondvalve plug 504, and the first passage 506 and the second passage 507converge downstream of the second valve port 517 and are incommunication with the outlet 502.

That is, the first valve port 516 is opened or closed by changing thelocation of the first valve plug 503, to control closure or opening ofthe first passage 506 in communication between the inlet 501 and theoutlet 502, thereby implementing the opening or closure function of theelectromagnetic valve described above. Similarly, the second valve port517 is open or closed by changing the location of the second valve plug504, thereby implementing the throttle function of the electronicexpansion valve.

The first passage 506 and the second passage 507 can be respectively incommunication with the inlet 501 and the outlet 502 in any suitablearrangement manner. To reduce an overall occupied space of the valvebody 500, as shown in FIG. 15, the second passage 507 and the outlet 502are provided toward a same direction, the first passage 506 is formed asa first through hole 526 perpendicular to the second passage 507, theinlet 501 is in communication with the second passage 507 through asecond through hole 527 provided on a sidewall of the second passage507, and the first through hole 526 and the second through hole 527 areseparately in communication with the inlet 501. The first through hole526 and the second through hole 527 are spatially disposedperpendicularly to each other or in parallel to each other. This is notlimited in this disclosure, and belongs to the protection scope of thisdisclosure.

To further reduce the overall occupied space of the valve body 500, asshown in FIG. 18 to FIG. 21, the inlet 501 and the outlet 502 areprovided on the valve body 500 perpendicularly to each other. In thisway, as shown in FIG. 18 to FIG. 20, every two of an axis of the inlet501, an axis of the outlet 502 (that is, an axis of the second passage507), and an axis of the first passage 506 are set perpendicularly toeach other, to avoid interference caused by movements of the first valveplug 503 and the second valve plug 504, and maximize utilization of aninner space of the valve body 500.

As shown in FIG. 14 and FIG. 15, to easily close and open the firstvalve port 516, the first valve plug 503 is disposed coaxially with thefirst valve port 516 along a moving direction, to selectively plug up ordetach from the first valve port 516.

To easily close and open the second valve port 517, the second valveplug 504 is disposed coaxially with the second valve port 517 along amoving direction, to selectively plug up or detach from the second valveport 517.

As shown in FIG. 17, to ensure reliability of plugging up the firstpassage 506 by using the first valve plug 503, the first valve plug 503may include a first valve stem 513 and a first plug 523 connected to anend portion of the first valve stem 513, and the first plug 523 is usedfor pressing against an end face of the first valve port 516 in asealing manner to plug up the first passage 506.

To easily adjust the opening degree of the throttle port 505 of theexpansion switch valve, as shown in FIG. 14 and FIG. 15, the secondvalve plug 504 includes a second valve stem 514, an end portion of thesecond valve stem 514 is formed as a conical head structure, and thesecond valve port 517 is formed as a conical hole structure fitting theconical head structure.

The opening degree of the throttle port 505 of the expansion switchvalve may be adjusted by moving the second valve plug 504 upward anddownward, and the upward and downward moving of the second valve plug504 may be adjusted by using the second electromagnetic drive portion522. If the opening degree of the throttle port 505 of the expansionswitch valve is zero, as shown in FIG. 14, the second valve plug 504 islocated at a lowest location, the second valve plug 504 plugs up thesecond valve port 517, and none of the refrigerant can pass through thethrottle port 505, that is, the second valve port 517. If the throttleport 505 of the expansion switch valve has an opening degree, as shownin FIG. 15, there is a gap between the conical head structure of the endportion of the second valve plug 504 and the throttle port 505, and therefrigerant flows to the outlet 502 after being throttled. If theopening degree of the throttle port 505 of the expansion switch valveneeds to be increased, the second electromagnetic drive portion 522 maybe controlled to move the second valve plug 504 upward, to make theconical head structure depart from the throttle port 505, so that theopening degree of the throttle port 505 is increased. In contrast, whenthe opening degree of the throttle port 505 of the expansion switchvalve needs to be decreased, the second valve plug 504 may be driven tomove downward.

During use, when only the electromagnetic valve function of theexpansion switch valve needs to be used, as shown in FIG. 14, FIG. 17,and FIG. 20, the first valve plug 503 detaches from the first valve port516, the first valve port 516 is in an open state, the second valve plug504 is located at a lowest location, and the second valve plug 504 plugsup a throttle port 505, so that the refrigerant that flows from theinlet 501 to the internal passage cannot pass through the throttle port505, and can only flow into the outlet 502 through the first valve port516 and the first through hole 526 in sequence. When the electromagneticvalve is powered off, the first valve plug 503 moves leftward, and thefirst plug 523 is separated from the first valve port 516, so that therefrigerant may pass through the first through hole 526. When theelectromagnetic valve is powered on, the first valve plug 503 movesrightward, and the first plug 523 is in close contact with the firstvalve port 516, so that the refrigerant cannot pass through the firstthrough hole 526.

It should be noted that in FIG. 14 and FIG. 20, a dashed line with anarrow indicates a flowing route and a direction of the refrigerant whenthe electromagnetic valve function is used.

When only the electronic expansion valve function of the expansionswitch valve needs to be used, as shown in FIG. 15 and FIG. 21, thesecond valve port 517, that is, the throttle port 505, is in an openstate, and the first valve plug 503 plugs up the first valve port 516,so that the refrigerant that flows from the inlet 501 to the internalpassage cannot pass through the first through hole 526, and can onlyflows to the outlet 502 through the second through hole 527 and thethrottle port 505 in sequence, and the opening degree of the throttleport 505 can be adjusted by moving the second valve plug 504 upward anddownward.

It should be noted that in FIG. 15 and FIG. 21, a dashed line with anarrow indicates a flowing route and a direction of the refrigerant whenthe electronic expansion valve function is used.

When both the electromagnetic valve function and the electronicexpansion valve function of the expansion switch valve need to be used,as shown in FIG. 12, FIG. 18, and FIG. 19, a dashed line with an arrowindicates a flowing route and a direction of the refrigerant, the firstvalve plug 503 detaches from the first valve port 516, the first valveport 516 is in an open state, and the throttle port 505 is in an openstate, so that the refrigerant that flows to the internal passage mayflow to the outlet 502 separately through the first passage 506 and thesecond passage 507. Therefore, the expansion switch valve has both theelectromagnetic valve function and the electronic expansion valvefunction.

It should be understood that the foregoing implementation is merely anexample of the expansion switch valve, and is not intended to limit thisdisclosure. Other expansion switch valves having both the expansionvalve function and the switch valve function are also applicable to thisdisclosure.

This disclosure further provides an electric vehicle, including the heatpump air-conditioning system according to this disclosure. The electricvehicle may be a pure electric vehicle, a hybrid electric vehicle, and afuel cell vehicle.

Although preferred implementations of this disclosure are described indetail above with reference to the accompanying drawings, thisdisclosure is not limited to specific details in the foregoingimplementations. Various simple variations can be made to the technicalsolutions of this disclosure within the scope of the technical idea ofthe present invention, and such simple variations all fall within theprotection scope of this disclosure.

It should be further noted that the specific technical featuresdescribed in the foregoing specific implementations can be combined inany appropriate manner provided that no conflict occurs. To avoidunnecessary repetition, various possible combination manners will not beotherwise described in this disclosure.

In addition, various different implementations of this disclosure mayalternatively be combined randomly. Such combinations should also beconsidered as the content disclosed in this disclosure provided thatthese combinations do not depart from the concept of this disclosure.

What is claimed is:
 1. A heat pump air-conditioning system, comprising:a Heating Ventilation and Air Conditioning (HVAC) assembly, acompressor, and an outdoor heat exchanger, wherein the HVAC assemblycomprises an indoor condenser, an indoor evaporator, and a dampermechanism, the damper mechanism is used for selectively opening aventilation channel to the indoor condenser or a ventilation channel tothe indoor evaporator, an outlet of the compressor is in communicationwith an inlet of the indoor condenser, an outlet of the indoor condenseris in communication with an inlet of the outdoor heat exchangerselectively through a first throttle branch or a first through-flowbranch, an outlet of the outdoor heat exchanger is in communication withan inlet of the indoor evaporator selectively through a second throttlebranch or a second through-flow branch, an outlet of the indoorevaporator is in communication with an inlet of the compressor, theoutlet of the indoor condenser is further in communication with theinlet of the compressor through a third throttle branch that isselectively open or closed, and the outlet of the outdoor heat exchangeris further in communication with the inlet of the compressor through afourth throttle branch that is selectively open or closed.
 2. The heatpump air-conditioning system according to claim 1, wherein a firstswitch valve and a first throttle element are connected in series to thethird throttle branch, and a second switch valve and a second throttleelement are connected in series to the fourth throttle branch.
 3. Theheat pump air-conditioning system according to claim 2, wherein thefirst throttle element is a capillary tube or an expansion valve, andthe second throttle element is a capillary tube or an expansion valve.4. The heat pump air-conditioning system according to claim 1, whereinthe first through-flow branch is provided with a third switch valve, andthe first throttle branch is provided with a first expansion valve. 5.The heat pump air-conditioning system according to claim 1, wherein theheat pump air-conditioning system further comprises a first expansionswitch valve, an inlet of the first expansion switch valve is incommunication with the outlet of the indoor condenser, an outlet of thefirst expansion switch valve is in communication with the inlet of theoutdoor heat exchanger, the first throttle branch is a throttle passageof the first expansion switch valve, and the first through-flow branchis a through-flow passage of the first expansion switch valve.
 6. Theheat pump air-conditioning system according to claim 1, wherein thesecond through-flow branch is provided with a fourth switch valve, andthe second throttle branch is provided with a second expansion valve. 7.The heat pump air-conditioning system according to claim 6, wherein theheat pump air-conditioning system is applied to an electric vehicle, andthe heat pump air-conditioning system further comprises a plate heatexchanger, wherein the plate heat exchanger is disposed inside thesecond through-flow branch, and the plate heat exchanger is alsodisposed inside a motor cooling system of the electric vehicle.
 8. Theheat pump air-conditioning system according to claim 7, wherein arefrigerant inlet of the plate heat exchanger is in communication withthe outlet of the outdoor heat exchanger, and a refrigerant outlet ofthe plate heat exchanger is in communication with an inlet of the fourthswitch valve.
 9. The heat pump air-conditioning system according toclaim 7, wherein the motor cooling system comprises a motor, a motorheat dissipater, and a water pump that are connected in series to theplate heat exchanger to form a loop.
 10. The heat pump air-conditioningsystem according to claim 1, wherein the heat pump air-conditioningsystem further comprises a second expansion switch valve, an inlet ofthe second expansion switch valve is in communication with the outlet ofthe outdoor heat exchanger, an outlet of the second expansion switchvalve is in communication with the inlet of the indoor evaporator, thesecond throttle branch is a throttle passage of the second expansionswitch valve, and the second through-flow branch is a through-flowpassage of the second expansion switch valve.
 11. The heat pumpair-conditioning system according to claim 10, wherein the heat pumpair-conditioning system is applied to an electric vehicle, and the heatpump air-conditioning system further comprises a plate heat exchanger,wherein a refrigerant inlet of the plate heat exchanger is incommunication with the outlet of the second expansion switch valve, arefrigerant outlet of the plate heat exchanger is in communication withthe inlet of the indoor evaporator, and the plate heat exchanger is alsodisposed inside a motor cooling system of the electric vehicle.
 12. Theheat pump air-conditioning system according to claim 11, wherein themotor cooling system comprises a coolant trunk, a first coolant branch,and a second coolant branch, a first end of the coolant trunk isselectively in communication with a first end of the first coolantbranch or a first end of the second coolant branch, and a second end ofthe first coolant branch and a second end of the second coolant branchare in communication with a second end of the coolant trunk, wherein amotor, a motor heat dissipater, and a water pump are connected in seriesto the coolant trunk, and the plate heat exchanger is connected inseries to the first coolant branch.
 13. The heat pump air-conditioningsystem according to claim 1, wherein the heat pump air-conditioningsystem further comprises a gas-liquid separator, the outlet of theindoor evaporator is in communication with an inlet of the gas-liquidseparator, and an outlet of the gas-liquid separator is in communicationwith the inlet of the compressor.
 14. The heat pump air-conditioningsystem according to claim 1, wherein the HVAC assembly further comprisesa PTC heater, and the PTC heater is used for heating air flowing throughthe indoor condenser.
 15. The heat pump air-conditioning systemaccording to claim 14, wherein the PTC heater is disposed on a windwardside or a leeward side of the indoor condenser.
 16. An electric vehicle,comprising the heat pump air-conditioning system according to claim 1.17. The heat pump air-conditioning system according to claim 8, whereinthe motor cooling system comprises a motor, a motor heat dissipater, anda water pump that are connected in series to the plate heat exchanger toform a loop.